Framing inside basement glass block windows

I am in the process of finishing my basement and am not sure how to proceed with the window boxes. The windows are glass block which is surrounded by concrete block.

I was thinking of finishing using wood for a deep "sill" and drywall on the top and sides but am unsure as to how to frame it or deal with the transition between the concrete and the glass block given the small margins?

I have done exactly as you have with framing. In one area, I did drywall on the bottom and sides of the opening, left a gap so it's not touching the walls just in case water should get into the window.

In my basement office, I framed it all in nice wood. They both look really nice. Just wish I could upload the image.

OK, I think the image uploaded...

Ignore the fact that it's pretty dirty, don't use that corner of the basement often and still need to finish repainting the window.

I would just do a simple drywall return right into the glass block. Why you would want to leave the block exposed is beyond me. Just use some of the L edge for 1/2" drywall where it meets the glass block and call it a day.

What dimensions did you rough in that framing to? What does it match up with the cinder block?

In my case, I couldn't drywall to cover the block because it would have left too narrow a gap to open the window, but yes I could have finished it off a little nicer for sure with some thinner material.

Actually when they are clean, they look pretty nice, not perfect, but nice.